Low slung railroad car



Nov. 25, 1969 G. cRoMPToN LOW SLUNG RAILROAD CAR 4 Sheets-Sheet 1 Filed Jan. 17. 196B Nov. 25, 1969 G. CROMPTON 3,479,968

LOW SLUNG RAILROAD rCAR Filed Jan. 17, 1968 4 Sheets-Sheet 2 if y /g Nov. 25, 1969 G. cRoMPToN 3,479,968

LOW SLUNG RAILROAD CAR Filed Jan. 17, 1968 4 Sheets-Sheet 5 Nov. 25, 969 G. cRoMPToN 3,479,968

LOW SLUNG RAILROAD CAR Filed Jan. 17, 1968 4 Sheets-Sheet 4 IN VEN TOR.

United States Patent O U.S. Cl. 10S-238 6 Claims ABSTRACT F THE DISCLOSURE A low slung railroad car the bottom of the body of which extends well below the axles of the wheels which are abnormally large in diameter and which are set just outside narrow portions of the car, the wheels having independent axles.

This application is a continuation-in-part of -my copending application Ser. No. 464,599, tiled I une 11, 1965, now abandoned, and is also copending with my application Ser. No. 663,386, led Aug. 25, 1967.

One object of the invention is to provide a railroad car construction of such character that a lot of them can be made up into a train that will go 200 miles an hour on existing tracks and can go fast around curves without tipping over or disrupting the track. Another object is to provide a car having a low center of gravity. Another object is to provide a lightweight car.

Another object is to provide a car having driving wheels of large size. Another object is to provide a train which will go around sharp curves without squeaking. Another object is to improve the rolling qualities of a railroad car by reducing vibration and friction through the provision of abnormally large diameter wheels.

Other objects will be apparent Ior pointed out hereinafter.

In the accompanying drawings illustrating one of many possible embodiments of the railroad car and also arl improved locomotive to draw a train of such cars (from Serial No. 663,386),

FIGURE 1 is a diagram of the locomotive,

FIGURE 2 is a diagram of the car,

FIGURE 3 is a side elevation of a wheel for the car which is also a wheel for the locomotive,

FIGURE 4 is an outside elevation of a stator for the car which is also a stator for the locomotive,

FIGURE 5 is a vertical cross section through a car (also a locomotive) according to the invention some parts being in elevation,

FIGURE 6 is an inside elevation of the field pieces (poles) and their cylindrical casings,

FIGURE 7 is the wiring diagram, in which the windings 119 making the poles A-J are in full lines, the connections from the generator and ground to the terminals 2, 6 and 10 are in full lines and the connections between the windings 119, A-J are in dash lines,

FIGURE 8 is a side elevation of a railroad (railway) car according to the invention,

FIGURE 9 is a plan View of the railroad car, the roof, the ceiling, the bus bars and the field pieces (stators) being omitted, for simplicity and clarity.

3,479,968 Patented Nov. 25, 1969 ICC Referring first to FIGURE l which is a diagrammatic plan view, the suggested outline of the locomotive L is shown in dash lines. I provide a prime mover P.M. In railroads that are electrified, this can be an electric motor of the type which they are now using. Examples are the Pennsylvania Railroad between New York and Washington, the New Haven Railroad between New York and New Haven, Conn., and parts of the Illinois Central. The prime mover drives a generator marked Gen. in FIG- URE l. If possible, they will be directly connected, and in case the P.M. is an electric motor, the pair of them constitute what is known as a converter.

The generator Gen. is a polyphase generator which produces a rotating magnetic eld by suitable poles made of coils of the eld of a motor connected to it. These poles constitute eld pieces 1. I have based my calculations on a 3 phase generator and motor as these are the only kinds now in extensive use so far as I know; I mean among multi-phase generators and motors.

The generator terminals are set apart, electrically. They transmit electric current to eld pieces 1L and 1R; the L indicating left, the R indicating right. Referring now to FIGURE 4, each eld piece (1L shown) has three terminals- 2, 6, and 10. 2 stands for two oclock, 6 stands for six oclock, and 10 stands for ten oclock. Two oclock is 120 from six oclock, six oclock is 120 from ten oclock, and ten oclock is 120 from two oclock. Six oclock, 6, is the ground terminal. Geometrically 2, 6 and 10 are arranged as shown in FIGURE 4 for stator 1L and the same but 4mirrored for stator 1R.

As shown in FIGURE 1, a terminal of the generator is connected by a line 13 to ground, as indicated by the .ground symbol, this meaning the framework of the locomotive. The terminals 6 of the field pieces are also connected to ground. One terminal of the generator is connected by a line 14 to a box marked RH CB. This is diagrammatic of a rheostat and a circuit breaker which are in series. A line 16 connects the box RH CB to a central pole 20 of a double pole double throw switch 21.

A line 24 from the generator goes to another box RH CB, which is another rheostat and circuit breaker in series, and from that a line 26 goes to a central pole 30 of the double pole double throw switch 21.

The poles 20 and 30 can be connected to poles 31 and 32, in which case the terminal 2 of 1L and the terminal 10 of 1R are energized at one phase and the terminal 2 of 1R and 10 of 1L are energized at another phase, the terminals 6 being grounded and representing the third phase. From FIGURE 1 it will be seen that this is the case both with the forward field pieces to the right of FIGURE 1, and the rear eld pieces to the left of FIG- URE 1. The conductor lines which represent cables and bus bars are so clear that I havent numbered them. Remember the convention that crossing lines are not connected unless there is a distinct dot where they cross.

In FIGURE 2 the terminals 2, 6 and 10` are clearly identified, both right and left and front and rear. The train is considered to be going to the right in FIGURES l and 2. The suggested outline of the car C is shown in dash lines. The eld pieces 1 are shown but no L and R are given because they become reversed when the car goes the other way.

The locomotive has electrical cable couplers 41 and 42 and the car C has electrical cable couplers 43 and 44. When the train is made up these are connected as shown in FIGURE 2, 41 to 43, and 42 to 44. I also show couplers 43 and 44 at the rear end of the car C, Couplers 43 and 43 are connected by a long cable 45 overhead in the car, Couplers 44 and 44 are connected by a long cable 46 overhead in the car. Locomotive and cars are grounded together.

Referring no-w to FIGURE 5, the locomotive has a pair of driving wheels 51 and 52. Preferably, according to my invention, each locomotive or car has only four wheels, and again preferably, according to my invention, each wheel is a driver.

The wheels 51 and 52 have treads 53 and 54 and anges 55 and 56. The treads 53 and 54 are shown as resting on railheads 57 and 58 supported by webs 59 and `60 supported by flanges 61 and 62 held to ties or sleepers 63 by spikes 65 and 66. Rails 57, 59, 61 and 58, 60, 62 are standard American rails, and although they differ, I will say for a `first-class railroad, So are the ties or sleepers 63 standard and they are made of wood and a tie 63 is shown in section. The rails are shown in section. I show a clearance between the flange 55 and the railhead 57 to provide for the cant going around sharp curves.

It will be seen that the axles for the wheels 51 and 52 are not the same, that is to say these wheels have twoaxles whereas in regular railway construction each pair of wheels right and left has one axle rigidly connecting the two, which is why the wheels squeak when the train goes around any sharp curve. That is, when a pair of wheels are rigidly connected to a single axle, the wheels have to rotate at the sarne r.p.m., whereas the outside rail is longer than the inside rail.

I contemplate that my wheels 51 and 52 will be six feet, 72 inches, in diameter at the treads. This makes them about 79 inches in diameter at the flanges. This is not unusual; it was frequent practice in steam locomotives before they were discarded in favor of diesels. The Atlantic type was built for the Atlantic Coast Line in 1895 and used later on by the Chicago and Northwestern Railway and had drivers that were 74 inches diameter at the treads and 81 inches diameter at the flangesIhe Erie Railroad had Atlantics before 1905, the drivers stated to be 76 inches in diameter, whether treads or flanges not stated. The `first Atlantics used on the New York Central system had drivers 72 inches in diameter at the treads and 79 inches in diameter at the flanges. Other examples could be given, but these seem to be enough. See American Lo comotives by Edwin P. Alexander, Bonanza Books, New York, copyright 1950i.

These wheels 51 and 52 are spaced apart so that the insides of the railheads 57 and 58 can be four feet, eight and a half inches, apart, which is standard American gauge from Maine to Oregon, California to Florida.

The wheels 51 and 52 have spokes 71. These are covered on the outside by electroconductive plates 73 and 74. FIGURE shows the left hand wheel 51 in section at the top, and in elevation at the bottom, the tread 53 and the -ange 55 being broken away to show the spokes 71 and the plates 73 in elevation.

I contemplate that the treads 53, 54, the anges 55, 56, and the spokes 71 will be made of the same steels which the locomotive builders used to build the driving wheels of the locomotives herein mentioned. They werent a1- ways the same, but they were generally similar steels. So also the hubs 75 and 76 should be ymade of the same steels as were used. The hubs 75 and 76 have axles 77 and 78 which are headed as shown and integral `with as by shrink iitting into the hubs 75 and 76. The axles have collars 79, and one not shown on the right which is similar, held in place by taper pins 81 on the left and one not shown on the right which is the same. The axles 77 and 78 t in journal bearings y83 and 84, 85 and 86, each being a half bearing to permit assembly. Some play is allowed between .4 each wheel and the bearings and the side of the car as indicated.

FIGURE 3 shows plates 74 which cover the spokes 71 behind them. The plates 73 and 74 should be made of highly conductive metal, and I select copper. I prefer beryllium bronze, 99 Cu 1 B, because this is stronger than commercially pure copper yet it has nearly as much conductance. I do not recom-mend welding the copper plates to the spokes because of the difference in coeiiicient of expansion between copper and steel. These wheels and all their parts should be able to stand a temperature variation between say 40 below zero centigrade, which may be encountered in the Rocky Mountains in wintertime, up to 100 C. which is hotter than nature but the plates 73 and 74 will heat up due to the energy that they absorb. However, they are very well air-cooled, especially at two hundred miles per hour. Illustratively, the plates 73 and 74 can be secured to the spokes 71 by drilling through the plates into the spokes, tapping the spokes, counterboring the plates, and insering screws with heads fitting in the counterbores. This I have not illustrated as it is a common means for securing parts together and the screws may be assumed to be not in the section shown in FIGURE 5.

I contemplate that the locomotive and cars will be made of aluminum and/ or magnesium, with perhaps some parts made out of steel and tops made out of fiberglass. The bearings `83 and 84, 85 and 86 can be made out of a good bearing bronze. I will now give an illustrative embodiment of the locomotive and car construction.

A long keel 90, extending the length of the locomotive or car, constitutes the floor and can be made of two parallel oor plates 91 and 92 joined together by end plates 93 and 94. The plates 93 and 94 can be welded to the plates 91 and 92. This keel 90 can be made of steel for strength.

The plates 93 and 94 are welded or otherwise secured to lower side pieces 95 and 96 made of aluminum. These have flanges at the top, shown only in the case of the flange 98 which is bolted by bolt and nut combinations 100 to upper aluminum side piece 102 opposite similar aluminum side piece 101 which has a iiange like the flange 99, but it isnt shown. In other words in FIGURE 5 at the right hand side I show the wheel 52 in elevation whereas the wheel 51 is shown on the left hand side in section and broken away.

On the left hand side I show the axle 77, the collar 79 and the pin 81, but on the right hand side these parts are broken away to show the flanges 98 and 99, and the bolt and nut combinations 100, but the construction is altogether the same on both sides although oriented differently.

The tops of the side pieces 101 and 102 are connected by a flat plate 105 made of aluminum; this can be welded onto the plates or fastened to them by bolts. This is the ceiling of the car. Above this is a roof 107 shown as being of inverted U shape, and this is desirably made of breglass because I dont want it to be electrically conductive. It can be attached to the side pieces 101 and 102 by bolts, not shown. The cables 45 and 46 are desirably made of copper and insulated by windings or by a coating of aluminum oxide as hereinafter discussed. They are upheld by U-shape hangers 109 and 110 having flanges like a capital U, which anges hold them in place. The hangers extend through slots in the roof 107 and to put them in place the slots are wider out of the section; in other words, this is a bayonet construction. The hangers can be made of methyl methacrylate, and this is bendable and insulating.

To complete the description of an illustrative embodi ment of the car construction, it can be, from end to end, the same as shown in FIGURE 5, but I much prefer that it shall be wider in the central section inside of the wheels. The limit of width is the same as that of the cars now in use on American railroads; that is to make them wider would create hazards in railroad yards where the curves are sharp.

Still referring to FIGURE 5, massive brackets 113 and 114, best made of steel for strength and permeability, are bolted to the side plates 101 and 102 and each one supports an annular casing made up of an inside steel cylinder 115 and an outside steel cylinder 117. They support eld pole 119 windings made of (best mode) soft iron ribbon.

The casing of 115-117 also supports a yoke 121 of soft iron ribbon. The turns of the windings 119 need insulation from each other and from the yoke 121 and from the casing 11S-117. The best material and method of application known to me is aluminum oxide, A1203 applied as described in Norton Companys U.S. Patent No. 2,707,691, W. M. Wheildon, Jr., trademark Rokide. Norton Company, Worcester, Mass., produces the aluminum oxide rods which are fed through a gun with a flame which melts the oxide (M.P. 2015 C.) and sprays it onto any article desired. I Wrote the patent. This coating is refractory and electrically nonconductive and the ribbon can Ibe bent after spraying.

The yoke 121 may be constructionally a soft iron ribbon wound round and round and round a mandrel of the same diameter as the cylinder 115 until the Wound ribbon will just t into the cylinder 117. The turns should be spot welded in many places to each other to form a rigid annular disc.

Referring now to FIGURE 6, the windings 119 make up individual pole pieces, nine in number, in the best mode of the invention, marked A, B, C, D, E, F, G, H, and J. Each pole piece is a sector of an annulus and it is not necessary to draw each of AJ. FIGURE 6 is an elevation looking outwardly from the wheel 51.

In order further to elucidate the construction of the fields, it seems best to described how they are put together and I shall take the one supported by the bracket 113, FIGURE 5. The bracket 113 is in the locomotive shop. The yoke 121 is made and then drilled at 2, 6 and 10 midway between 115 and 117 to make room for bronze bolts to connectjto the 3 phase power.

The nine pole pieces A, B, C, D, E, F, G, H and I are then made and space is left in the centre of each for the Ibronze bolts 27 6 and 10. Also the Rokide is left olf the outside and inside ends of the iron or copper ribbons which can be readily done by masking. Rokide flame doesnt burn good grade masking tape.

The eXact length of ribbon to make each pole will be discovered by trial winding. Enough length is provided for each pole to extend from the outside thereof to the inside of the proper pole for the electrical connections, as the poles A-J are to be connected in series. Now the yoke 121 is inserted in the bracket 113 between 115 and 117. The ribbon ends are drawn across the far faces. FIGURE 6, of the pole pieces, so they are not visible in FIGURE 6. Thereby they are buried; otherwise they might be caught by the 200 mile an hour wind and the entire set of windings destroyed. Then the poles A-I are inserted, matching the holes. Then the unrokided ends of the ribbons are welded together. The bolts 2 and 10 are now inserted and welded to the ends of the ribbons in the holes. The ribbon ends are turned (bent) 90 edgewise to go atwise from the periphery of one sole to the center of a connected pole. The Rokide coating will stand it.

The bolts 2 and 10 are Rokided where they pass through the bracket 113, and the yoke 121. They are headless and have shoulders to engage the inside of the bracket 113. They are screw driver slotted too. The bolts 6 are Rokided in the yoke 121, threaded in the bracket 113 and have heads.

The bracket 113 is now placed so that the geometrical faces of the poles A-J are horizontal (it might have been this way in the beginning). The casing 117 has been countersunk in many spots opposite A-I and the casing 115 desirably also. There is a small clearance here and there between the poles A-J and the cylinders 115-117. Molten magnetic metal is now poured into the crevices all around. This or some other method of holding the pole pieces in place in necessary. Plates extending from the bracket 113 could be used.

Now the bracket 113 is bolted to the side piece 101 as shown in FIGURE 5. I provide large bus bars 131, 132, 133 and 134-see FIGURES 4 and 5. At this point the right and left geometry had better be studied. The locomotive and train were stated to be going to the right, FIGURES 1 and 2. In FIGURE 5 the eld piecesor stators 1L and 1R are clearly marked, so the sectional view of the wheel Iand the field piece on the left of FIG- URE 5 i-s on the left hand side of the locomotive.

In FIGURE 5 the reader is looking forward because left is left and right is right. The geometrical positions of the bolts 2, 6 and 10 are shown on FIGURES 4, 5 and 6. In FIGURE 5, at the right, the bolt 6 is hidden by the nuts on bolt 10. For the electrical connections to these bolts see the diagrammatic FIGURE 1 and also FIGURE 5.

Terminal 2 on the left is connected to bus bar 131 which is connected to cable 46. Terminal 10 on the right is connected to bus bar 132 which is connected to cable 46. FIGURE 4 is moving to the left, and it is on the left hand side of the locomotive. Terminal 10 on the left is connected to bus bar 133, and this is connected to cable 45. Terminal 2 on the right is connected by the bus bar 134 to cable 4S. The bus bars 131 and 134 have the same shape, and the bus bars 132 and 133 have the same shape.

The wiring diagram is shown in FIGURE 7 and it will be seen that the ribbon ends extend a long distance (angularly many degrees) in the stators. Therefore they need to be bent and I propose hot forging for the ribbon ends and Rokiding afterwards. Copper has the advantage (for the ribbon windings 119) of lower ohmic resistance, but iron has the advantage of enormously greater magnetic permeance (reciprocal of magnetic reluctance) than copper, and the windings 119 are in both an electric circuit and a magnetic circuit.

For the material of the bus 'bars 131, 132, 133 and 134 I select beryllium bronze, 98 Cu 2 Be, to provide high tensile strength, high elastic limit, high electrical conductivity and reasonable susceptibility to cold working. See the Encyclopaedia Britannica, vol. 3, page 541 left, article Beryllium, copyright 1963. The shapes of these bus bars are shown in FIGURES 4 and 5 but not completely, but I need only add that they should be streamlined, that is longer fore and aft than athwart. They can be elliptical in cross section with the major axes across the paper, FIGURE 4, say twice the minor axes. The upper parts `of the brackets 113 and 114 are also desirably elliptical in cross section, major 'axis fore and aft. However, where the bus bars are fastened to the brackets, both parts are flat (or shaped to fit nicely) and heavily Rokided around the holes.

All Rokide coatings are porous so the exposed parts of the eld piece poles, the edges of the ribbon windings, land the ribbon ends that connect pole to pole should be impregnated with some insulating organic material that will stand a temperature of C. (boiling water). This can be done just after pouring the magnetic metal. Val- Spar is good, it can be put on with a brush, Bakelite varnish is good. See Encyclopaedia Britannica article on resins. The cables 45 and 46 if Rokided can be varnished too. The varnish can be sprayed as well as put on with a brush. The brackets 113 and 114 and the bus bars should be Rokided where they contact or are close and they should be varnished too.

Resuming the description of the assembly, the bus bars 131, 132, 133 and 134 are now connected. They are put over the bolts 2 and 10 outside the bracket 113 and the bolts extend through the bus bars and are threaded only outside the bus bars when the latter are in place, plus maybe one turn to be sure to get a clamp. Using a screw driver in the slot to hold the bolt `from rotating, a nut is put onto the screw and screwed in. On the inside of the bracket 113 the shoulder holds Rokide to Rokide. This gives -a high coefficient of friction. The nut is tightened very tight then an outer or lock nut is screwed into place. Of course each bus bar is held upright during these proceedings. Then the bus bars 131, 132, 133 and 134 are connected to the cables 45 and 46 in the electrical arrangement described and the mechanical means of doing so comes within the general electrical art and need not be described. Here in I have specied a Rokide coating wherever insulation is needed and insulating organic material on the Rokide wherever it is exposed to the weather, and if I have inadvertently failed to mention insulation for a contact or near approach for parts needing insulation, the electrical engineer will know that I recommend Rokide and insulating organic material (resistant to boiling water) where the Rokide is exposed to the weather. After the assembly above described, all exposed parts of the bus bars 131-134 and brackets 113, 114 are Rokided, then varnished, to keep people from being electrocuted. Rokiding apparatus is portable. The brackets act as bus bars also.

Turning now to the left hand bottom side of FIG- URE I show a bumper 161 having a dovetail fitting in the corresponding groove in the side piece `95. There is another bumper 162 on the other side, FIGURE 5. These are engage-able with the rims of the Wheels 51 and 52 respectively, and the rims consist of the treads and the flan-ges. The insides of the rims are fiat as shown. This is in order that a great strain on the axle 77 or 78 due to :centrifugal force generated by fast speed around a curve shall not break anything since the llat side of the rim will contact bumper 161 or 162. The wheel being made of steel, I propose the same Iberyllium bronze, 98 Cu 2 Be, for the material of these bumpers, as steel on bronze has a low coefficient of friction and this bronze is strong, tough and wear-resistant. It will be seen that the hubs 75 and 76 can contact the projecting portions of the side pieces 95, 96, 101 and 102 without the wheels contacting the bumpers, but Ia slight further movement permitted by the elasticity of the wheels and the axles will bring the wheels into `contact with the bumpers. This provides a counterthrust far from the center of revolution which will prevent further motion. The bumpers 1161 and 162 can be driven into place and held from lengthwise movement by removable bolts, not shown. By removing these bolts the bumpers can be hammered to move them out of place to be replaced by new ones when they Ishow signs of wear.

When the locomotive engineer throws the switch 21 forward, the locomotive (or train) goes forward or to the rear. There are too many factors for me to figure this and it does not matter. The convention of switch to the rear, train forward is just as good as the convention switch forward train forward. This locomotive has just as much power and speed one way as the other; the difference is what the engineer can see.

The switch 21, 20, 30 is a current reversing switch and it engages the (electric) poles 31 and 32 or (electric) poles 171 and 172 and it will be seen from FIGURE l that the one connection is the reverse of the other one. Also the switch 21, 20, 30 is a circuit opening switch to allow the train to coast.

In driving from a station to high speed the main switch 21 should be opened whenever the speed is too great for the conditions. The rheostats RH should be in short circuit of the resistance coils. That is they are doing nothing. When at 180 miles per hour the engineer sees a truck stalled on the track three miles ahead, he has only one minute to stop the train, so he sets the electromagnetic brakes by moving the switch 21 to the opposite position in which the wheel motors are trying to reverse the train. This is a powerful brake-too powerful; it might cause the train to jump the track. This is where the rheostats come in. Before changing the switch 21 to reversing train position, the rheostats are put into full resistance position then gradually moved towards short circuit position until the negative acceleration is as high as need be for the conditions. Merely opening the switch 21 will cause suflicient slow down on account of wind resistance and friction for most purposes but for making anice landing at a station the use of the electromagnetic brake plus the rheostats is recommended.

I have stated that molten magnetic :metal is poured into the crevices between the pole pieces A-I and the casings and 117. I have also said that the windings can be iron (steel) or copper, iron and steel being preferred, iron being the generic name. The melting point of iron, which is magnetic, is l535 C., of cobalt, which is magnetic, is 1495 C., of nickel, which is magnetic, is 1455 C. Any of these or alloys can be used even with copper ribbon, M.P. 1083 C. because Rokide that is aluminum oxide is a thermal insulator and the molten metal will freeze fast. Good examples of magnetic metal alloys for use here are manganese steel, 88 Fe 11 Mn 1C M.P. 1290 C., Hastelloy D, 90 Ni 3 Co 1.5 Al 5.5 Si M.P. ll60 C., and any of the stellites, M.P. 1250-1275, see p. 1528 of the Handbook of Physics and Chemistry, The Chemical Rubber Co., Cleveland, Ohio. The stellites are cobalt based alloys. In this specication pole pieces, lield pieces and sometimes poles are synonymous.

It will thus be seen that there has been provided by this invention a low slung railroad car in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments can be made of the invention and as Imany changes can be made in the embodiment described herein; it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. A low slung railroad car comprising a car body with vertical side walls mounted on opposed pairs of independent rail Wheels, said wheels having a height greater than one-half the height of the side walls and having rims comprising treads and flanges to t a railroad track, said wheels being -mounted on independent axles mounted in said car body, said car body extending well below said axles and having a wide portion which is positioned between two narrow portions, said rail Wheels being positioned entirely outside the narrow portions and within planes deiined by extensions of the wide portion, the narrow portions being entirely between the wheels at all portions of the latter and not on top of the wheels.

2. A low slung railroad car according to claim 1 in which at least one wheel is a driver.

3. A low slung railroad car comprising: a car body with vertical side walls mounted on an opposed pair of independent rail Wheels, said wheels having a height greater than one-half the height of the side walls and having rims comprising treads and flanges to it a railroad track, said Wheels being mounted outside of said side walls on independent axles mounted in said car body, said car body extending well below said axles, and bumpers between the rims of the Wheels and adjacent Vertical side walls, said bumpers spaced from the rims by a small clearance and secured to the Vertical side walls well below the axles, with the respective bumpers contacting the rims when the clearance between the car body and the rims is narrowed due to the action of centrifugal force on the wheels.

4. A low slung railroad car according to claim 3 in which the bumpers are removable from the car body for replacement.

5. A 10W slung railroad car according to claim 4 in which at least one Wheel is a driver.

6. A low slung railroad car according to claim 3 in which at least one Wheel is a driver.

References Cited UNITED STATES PATENTS 9/1873 Yates 105-238 3/1884 Cooke 105-37 X 6/ 1890 Baldwin 105-26 4/ 1893 Stuebner 105-157 7/ 1898 Halbert 10S-215 X 6/1910 Fowler 10S-133 X 8/ 1912 Krause 10S-217 X 5/ 1922 Cochran 293,--58 6/ 1929 Ackerman 105-26 6/ 1933 Tessmer 105-397 Hick 10S- 364 Edmunds 105--218 Willoughby 10S-364 Aske 3104-268 Brennan 213-221 Omar et al. 1054 Dexter 310-211 Lee 310-166 Mulhaupt 10S-215 X ARTHUR L. LA POINT, Primary Examiner HOWARD BELTRAN, Assistant Examiner U.S. Cl. XR. 

